1. Field of the Invention
The present invention relates to structurally reinforced elastomeric articles, and in particular relates to such articles as employed as breaker belts for pneumatic tires.
2. Description of the Prior Art
A. Structurally Reinforced Elastomeric Articles
A variety of structurally reinforced elastomeric articles are taught in the prior art. For example, Reynolds in U.S. Pat. No. 2,003,494, teaches an insulating and packing laminate of a metal foil having holes therein and an elastic layer binding to the foil through the holes. Similar structural arrangements are taught by Beals in U.S. Pat. No. 84,932 and in British Pat. Nos. 786,233 and 450,151 to be useful as rubber matting. Kilduff teaches a somewhat related structure employed as an electrically conductive adhesive tape; see U.S. Pat. No. 3,505,144.
Newell in U.S. Pat. No. 2,747,701, discloses a reinforced brake lining comprising a wire mesh embedded in a standard brake liner composition. U.S. Pat. No. 2,304,263 to Loty teaches a wire mesh having opposing adhesive coatings thereon, as useful for laminating plywood together.
B. Breaker Belts for Pneumatic Tires
In the tire industry, it is standard practice to insert a reinforcing belt between the tread layer and the carcass, in order to prolong the useful tread life. These belts are generally made up of one or more layers of parallel strands of inextensible cords, for example steel wires, each embedded in an elastomeric material such as rubber, and running in a complete circle or in a helix around the tire. These belts do indeed prolong the life of a tire tread compared to that of beltless tires, primarily because of the rigidity of the breaker belts employed. This rigidity minimizes the drag that accompanies the forward and reverse directions of the vehicle, which drag is the principal cause of tread wear. Examples of such breaker belt construction are disclosed in the following U.S. patents: U.S. Pat. Nos. 3,195,602 to Keefe; 3,335,777 to Hutch; 3,095,026 to Weber; 3,637,003 to Clapson; 3,172,445 to Boussu et al; 3,667,529 to Mirtain; and 3,192,984 to Bourdon.
Additional prior art patents teaching other breaker belt arrangements include: U.S. Pat. Nos. 3,532,150 to Wittneben; 3,500,889 and 3,500,890 to Boileau; 3,667,529 to Mirtain; 3,205,931 to Keefe; 3,623,527 to O'Neil; 3,480,065 to Verdier; 3,509,929 to Delobelle; 3,231,000 to Massoubre; 3,558,389 to Bezbatchenko; 3,090,417 to Spelman; 3,253,635 to Travers; 2,792,868 to Benson; and 3,643,723 to Mukao. This list is not complete.
C. Radio Frequency Conductive Heating in the Manufacture of Pneumatic Tires
Pneumatic tires employing steel cord construction have been manufactured by radio frequency inductive heating of the elastomeric material causing bonding to the steel cord. Mittlemann, in U.S. Pat. No. 2,545,370 teaches the use of two radio frequency inductive heaters as used in the manufacture of rubber coated steel belts. Other inductive heating techniques are disclosed in the article "Inductive Heating and Tempering" in the METALS HANDBOOK of the American Society of Metals, 7th Edition Supplement, August 15, 1955, on page 107.